International Registry of Intra-arterial and Endosaccular Flow Diverters (IRF)

Technical Success will be determined by successful deployment of the flow diverter stent or endosaccular flow disruptors. A dichotomous determination (i.e., Yes/No) will be made and summarized for this study.

Procedural complications will be identified as the number of instances of the following adverse clinical events: In-stent Thrombosis/Stenosis; Ischemic complications (Transient Ischemic Attack/Stroke), Intracerebral hemorrhage, Aneurysm rupture, and Vessel occlusion due to flow diverter stent or endosaccular flow disruptor placement.

Clinical outcomes at discharge will be assessed using the modified Rankin Scale (mRS) for neurologic disability. The mRS is a 6-point disability scale with possible scores ranging from 0-5. mRS measures the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. Higher scores are generally associated with less favorable outcomes. For this study patients with an mRS score of 0-2 will be determined to have had a "favorable" outcome to the procedure and patients with an mRS score of 3-5 will have been determined to have had an "unfavorable" outcome.

Clinical outcomes at last available follow-up will be assessed using a variant of the modified Rankin Scale (mRS) for neurologic disability. The classic mRS is a 6-point disability scale with possible scores ranging from 0-5. mRS measures the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. Higher scores are generally associated with less favorable outcomes. For this study patients with an mRS score of 0-2 will be determined to have had a "favorable" outcome to the procedure and patients with an mRS score of 3-5 will have been determined to have had an "unfavorable" outcome. Scoring will also include a 6 to identify patients who have expired.

Immediate Angiographic Outcomes at Discharge will be evaluated using the OKM grading scale. The OKM scale will be used to assess the degree of angiographic filling and in the setting of intracranial aneurysms which were treated by endovascular flow diversion. It is used to predict aneurysm closure over time. Patient outcomes will be stratified based on the following scale scores: Grade A: Total filling (>95% of aneurysm remained); Grade B: Subtotal filling (5-95% of aneurysm remained); Grade C: Entry remnant (<5% aneurysm remained); and Grade D: No filling (0% aneurysm remained). As such, the less aneurysm remnant the more favorable the angiographic outcome. The number/percentage of cases of each OKM Grade will be summarized.

Immediate Angiographic Outcomes at Discharge will also be evaluated using mRRC categorization. mRRC categorization will be used to assess the degree of occlusion achieved when treating an intracranial aneurysm. It categorizes the level of residual contrast filling within an aneurysm after coiling. For purposes of this analysis, Class I will signify complete occlusion; Class II will signify Residual neck occlusion; Class IIIa will signify Residual aneurysm with contrast stasis; and Class IIIb will signify Residual aneurysm without contrast stasis. As such, it is an indicator of how effectively the aneurysm has been sealed off during treatment. The number/percentage of cases of each mRRC category will be summarized.

Immediate Angiographic Outcomes at Discharge will be evaluated using the WOS grading scale. The WOS is a standardized angiographic assessment scale for reporting aneurysm occlusion achieved with endosaccular flow disruptors and can be employed to assess the adequacy of treatment. For purposes of this analysis, WOS Grade A will signify complete occlusion; WOS Grade B will signify Residual neck occlusion; and WOS Grade C will signify Residual aneurysm filling. The number/percentage of cases of each WOS grade category will be summarized.

Immediate Angiographic Outcomes at Discharge will be evaluated using the OKM grading scale. The OKM scale will be used to assess the degree of angiographic filling and in the setting of intracranial aneurysms which were treated by endovascular flow diversion. It is used to predict aneurysm closure over time. Patient outcomes will be stratified based on the following scale scores: Grade A: Total filling (>95% of aneurysm remained); Grade B: Subtotal filling (5-95% of aneurysm remained); Grade C: Entry remnant (<5% aneurysm remained); and Grade D: No filling (0% aneurysm remained). As such, the less aneurysm remnant the more favorable the angiographic outcome. The number/percentage of cases of each OKM Grade will be summarized.

Immediate Angiographic Outcomes at Discharge will also be evaluated using mRRC categorization. mRRC categorization will be used to assess the degree of occlusion achieved when treating an intracranial aneurysm. It categorizes the level of residual contrast filling within an aneurysm after coiling. For purposes of this analysis, Class I will signify complete occlusion; Class II will signify Residual neck occlusion; Class IIIa will signify Residual aneurysm with contrast stasis; and Class IIIb will signify Residual aneurysm without contrast stasis. As such, it is an indicator of how effectively the aneurysm has been sealed off during treatment. The number/percentage of cases of each mRRC category will be summarized.

Immediate Angiographic Outcomes at Discharge will be evaluated using the WOS grading scale. The WOS is a standardized angiographic assessment scale for reporting aneurysm occlusion achieved with endosaccular flow disruptors and can be employed to assess the adequacy of treatment. For purposes of this analysis, WOS Grade A will signify complete occlusion; WOS Grade B will signify Residual neck occlusion; and WOS Grade C will signify Residual aneurysm filling. The number/percentage of cases of each WOS grade category will be summarized.

Radiation exposure over the course of the procedure will be extracted and summarized. Radiation exposure will be evaluated based on relevant imaging system metrics used to calculate the total radiation dose delivered to the patient based on the fluoroscopy time and the area of the X-ray field exposed during the procedure. Flow diverter stents and endosaccular flow disruptors typically result in significantly lower radiation exposure compared to other endovascular techniques for treating brain aneurysms due to a reduction in fluoroscopy time and overall reduced radiation dose due to the streamlined nature of the procedures.

The duration of procedure placement will be extracted and summarized. The duration of the procedure is influenced by the complexity of the aneurysm, the patient's anatomy, and the experience of the interventional radiologist and care team. Shorter procedure duration times are associated with more favorable outcomes.

The use of adjunctive devices such as coils, stents or balloons to further enhance aneurysm occlusion of the flow diverter stent or to facilitate positioning and deployment of the endosaccular flow disruptor within the aneurysm sac during the procedure will be extracted and summarized. The number of adjunct devices will be extracted and summarized.

The percentage of patients who experienced aneurysm recurrence will be extracted and summarized based on a binary (Yes/No) determination following retrospective record review. The span of time from initial treatment to recurrence will be assessed and summarized.

The percentage of patients who required retreatment for a recurrence of aneurysm will be extracted and summarized based on a binary (Yes/No) determination following retrospective record review. The span of time from initial treatment to retreatment will be assessed and summarized.